Simon Blanchard, Georgetown University. All mistakes are mine.

Calculating Pro and Anti Distortion in Multi-Option Choices.

As a supplement to our manuscript in Psych Science, I provide this template survey to help calculate pro/anti distortion in multi-option choices.

The present illustrative example is for a 4 restaurants choice, where all participants are choosing between Restaurant A, B, C, and D. This is in contrast to what's been done in previous distortion work, because all participants make a choice between the four options - not just those in a no-choice control condition.

Participants in the control condition (called NCC) evaluate the alternative information with the identity of the restaurants "hidden". This prevents the formation of tentative preferences to influencing attribute evaluations. Participants in the regular choice condition (called CC) proceed as usual. In the present template, there is only one order of the 6 attributes, and the order of the restaurants in the scrambling (NCC) condition is fixed.

It should be pretty self-explanatory, but some familiarity with SPSS syntax and Qualtrics is expected. Should you have any questions (or if you find any bug), e-mail Simon at


To download the Qualtrics survey template, click here (1. right click, 2. SAVE AS) (instructions on how to import surveys are here).

To download the associated SPSS syntax, click here (1. right click, 2. SAVE AS).

To download a copy of the manuscript, click here (PDF).